Various portable appliances for steam cleaning smooth surfaces such as plate glass have already been proposed.
Nevertheless, those portable appliances are generally low power appliances, designed to deliver a jet of steam through a dispenser manifold provided with a scraper, such that said appliances are well adapted only to cleaning surfaces that are smooth and hard, such as plate glass or tiles.
Steam-producing boilers are also known which enable steam to be obtained in sufficient quantity for thorough cleaning, but they make steam in an enclosure which also contains the water used to produce the steam, and as a result the boiler must be kept in a well-determined upright position, thereby preventing it from being integrated in a portable cleaner.
Another steam-producing system consists in using a labyrinth. A pump takes water from a tank and propels it to travel along a long path which is heated to a temperature below the critical temperature at which wetting ceases to occur, with the water being transformed progressively along the path into steam. Such a system suffers from the drawback of scaling up quickly and easily, of being relatively large, heavy, and expensive. In existing appliances of that type, it is also impossible to cut down or to increase to any significant extent the quantity of water droplets that are present in the outlet together with the steam.
Steam generators have also been proposed that are of the capillary type in which water is stored in a porous body that is put into contact with an electric heater member which enables steam to be produced instantaneously. That type of steam generator is lightweight, low cost, and relatively insensitive to scale, thereby giving it good lifetime in the context of a portable appliance.
Nevertheless, that type of steam generator has been used up till now only in the context of a low power appliance, given the difficulties associated with controlling heating, particularly when the appliance is to be used in various different positions. Steam cleaning appliances have thus been proposed which operate at a power that does not exceed 300 watts and which use a ceramic resistance element as the electric heater member. Such appliances can be used, for example, for cleaning plate glass, but they do not enable flexible surfaces such as the textile surfaces of seats, sofas, carpets, car seats, drapes, etc. to be cleaned effectively.